Collapsible form for concrete constructions



H. E. BILGER.

\ coLLAPslBLE FORM Foa CONCRETE coNsTRucuoNs.

APPLICATION FILED APR.-I2,1920. 1,373,548. Patented Apr. 5,1921.

4 SHEETSSHEET l.

f m nu@ H. E. Busan. COLLAPSIB'LE FORM FOR CONCRETE CONSTRUCTIONS.

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coLLAPslLE FORM Foa CONCRETE coNsTRucloNs.

S-SHEET 3.

APPLICATION FILED APR.12, |920. 1,373,548. Patented Apr. 5, 1921.

Patented Apr. 5, 1921.

APPLICATION FILED APR. 12, 1920.

4 SHEEIS-SHEEI 4.

UNITED STATES HARRY E. BILGER, 0F IYIONMOUT, ILLINOIS.

COLLAPSIBLE FORMFOR CONCRETE CONSTRUCTIONS.

Specification of Letters Patent.

Fatented Apr. 5, 1921.

Application filed April 12, 1920. Serial No. 373,144. Y

To all whom t may concern:

Be it lrnown that I, HARRY E. BILGER, a citizen of the United States,residing at Monmouth, in the county or' Warren and State of illinois,have invented a certain new and useful Improvement in Collapsible Formsfor Concrete Constructions (Case l), of which the following is a i'ull,clear, concise, and exact ncscription, reference being had to theaccompanying drawings, forming a part of this specification.

My invention relates to a collapsible form adapted i'oi' 'use inconstructing concrete culverts, bridges, sewers, aqueducts, etc. Amongits salient objects, my said invention contemplates lst. rlhe provisionor an apparatus of this class that is of steel throughout, and whichcomprises a comparatively iew large parts and no small parts that areapt to become lost or mislaid.

2nd. rllie provision oi' a Jorm of thisclass which, when assembled,presents a flat top and straight vertical sides to the concreteV whichis poured around and over the form when the latter is used.

3rd. The provision of a form of this class that readily may beassembled, collapsed and disassembled by a single workman.

4th. The provision of a form el this class wherein all similar parts oi'the apparatusY used inconstructing a culvert, bridge or the .like oii'any given size, are symmetrical and interchangeable to the end that theworkman assembling the form is not required to distinguish betweenrights and leitts.

5th. rll'he provision of an equipment comprising base members and coverplates capable ot use in building up a i'orm of any one of a pluralityol' sizes, together with a plurality of sets of form centers l, each setoi? form centers to be used in erecting a form of a certain size.

6th. An equipment of the class mentioned, all oi trie several parts oliwhich are or metal and so constructed that if broken, they can be easilyand quickly repaired by any blacksmith.

In the accompanying drawings several parts of the form assembled andready to have the concrete, which is to form the finished culvert,bridge or the like, placed over and around the same.

Fig. 2 is a longitudinal, vertical, sectional view taken on the line2-.2 of Fig. l, certain parts or' the apparatus being broken awaybecause of lack of space on the drawing" in y which to illustrate theform without broken parts on a suliiciently large scale.

Fig. 3 is a view in perspective of one of the two similar andinterchangeable base members of the form of my invention.

Fig. 4 is a view in perspective, with certain parts broken away,illustrating the form of the present invention in the course ofassembly.

Fig. 5 is a detailed, sectional view taken on line 5-5 of Fig. 2, thisview illustrating the means carried by the form centers for spacing thebase members.

Fig. 6 isa view similar to Fig. 5, illustrating a modilied and perhapspreferred means car ied by the form centers for the purpose of spacingthe base members.

Fig. 7 is a fragmentary side elevation of the form center parts shown inFig. 6.

Fig. 8 is a view similar to Fig. 2, illustrating a form of greaterheight and width than the form or" Fig. 2, the scale to which Fig. 8 isdrawn being such as to permit two oi the form centers to be shown,whereas in Fig. EZ it has been possible to illustrate but one of theform centers.

F ig. 9 is a vertical, sectional view taken on the line 9-9 of Fig. 8.

Fig. l0 is a view in perspective of one of the cover plates forming partof the apparatus or' my invention; and y Fig. il is a fragmentary,elevational view illustrating a modified `form center construc-`elusive, consists of base members lQ-l2,a

plurality ci term centers, one of which is illustrated at 13, a pair ofcorner cover plates Y ler-ld, and a plurality ot' channel shapedcoverplates 1li- 15. In the description oi the larger type of form shownin Figs. 8 and 9, lishall explain how these plates i-iiiay supplementthe corner plates 14C in providing a tlat top for the form. In thesmaller form oit Figs. l to 5, inclusive, the` plates l5 are employedmerely at the sides of the form.

The details of one of the base members 12 are illustrated in perspectivein Fig. 3. rlhe base member 12 is substantially L-shaped in crosssection. Velded, riveted or otherwise secured to each end of the basemember12 are short angle bars 1G'16, the vertical legs of which abutagainst the vertical sides of the base member, the purpose of the anglebars 16 being to widen the bottom of the base member at its ends andthus prevent the base member from tilting over when in use. Also securedtothe ends of the base member are the short angle bars 17-17, thehorizontal sides of which project beyond the horizontal side of the basemember andare disposed somewhat above the horizontal side of the basemember. As will presently appear, Vthe purpose of the angle bars 17 isto prevent the lateral pressure of the concrete from forcing thelowermost side cover plates under the base members.

The vertical side of each base member is provided with la plurality ofnotches 18, there being one ot these notches provided for every formcenter employed. .The topv edge oi the base member Vis inclined adjacentY the notches 18, as is indicated at 19-19. If

- base of substantial breadth.

it were not for the fact that I contemplate using either base member oneither side of the form, it would sufce to incline the top edge ofthebase member only at one side of each of the notches 18. I prefer,however, to incline the top edge at both sides of each notch in orderthat eachbase member may be used on either sideol the form.

Each of the form centers ofthe apparatus Vshown in Figs. 1 to 5comprises a steel plate 2O, which is turned laterallypat its upperVoblique flange 22, which constitutes the base of each form center, issupplemented by a metal angle 2 3, the lower surface Voit which isdisposed in the same plane with the lower surface of the oblique ange22, so that the lower surfaces of angle 23 and the oblique ange 22together constitute a form center j It is to be noted, however, that thebreadth of the form center base provided by angle 23 and oblique flange22 is less than the breadth of the base member notches 18. rlhe formcenter plates are stiffened at their lateral edges by steel angles 24,and may be provided with centrally disposed stiflening angles 25, ifdesired, the said angles 24 and 25 being riveted, welded or otherwisesuitably secured to their associated plate 20, as shown in Fig. 1.

like, I make the usual excavation to the nec-r Y essary depth, and thenput in the usual concrete base or floor indicated at 26. After theconcrete base or floor has set for some time, at least over night, I Vamready to position and assemble the form. rIhe base members sides oftheir adjacent base member notches 18. It will be noted that the obliqueflange Y 22 of each form center is provided with two pairs of downwardlyprojecting fingers 27, which may be in the form of rivets tightly drivenor welded in theV positions shown. Each pair of fingers 27 is designedto engage the vertical side of one of the base members 12, in order thatthe base members 12 may be held properly spaced apart. Y

vWhile I have shown but one form center in Fig. 2, it will be understoodthat at least two, and if desired a multiplicity, of these form centerswill be employed, there beingone form center disposed adjacent each oneVofthe base member notches 18. The form center plates 20 and theirlateral stifl'ening angles 24 are cut away, as indicatedv at 28, toprovide hooks 29, the-purpose of these hooks being to retain the coverplates 14 and 15 in position.

It will be noted that the flanges of the cover plates 14 and 15 aresuitably perforated to accommodate the hooks 29. I prefer to provideeach flange of each cover plate with suitably spaced apertures, in orderthat the said cover plates may be used, either side up or either end to.

After the form centers have been properly placed upon Vthe base members12, Vas liereinbefore described, the side cover plates 15 are placed inposition. When the said side cover plates are positioned, as shown inFig. 1, the form center hooks 29 pass freely through the apertures .inthe upper flanges of the side cover plates, and the lower flanges of thecover plates rest directly upon the base or floor 26. After the sidecover plates 15 have been placed in position, the corner cover plates 14are placed in position, the horizon al flange of' each corner coverplate resting upon the upper flange of one of the side cover plates 15,and the vertical flange of each corner cover plate resting upon the formcenters. The form center hoolrs 29, of course, pass freely through theapertures of the horizontal flanges of the corner cover plates, as isclearly illustrated in Figs. l and a.

Attention is directed to the fact that the side coverplates l5 restdirectly upon the concrete base or floor 26, and derive none of theirsupport from the form centers. Moreover, since the horizontal flanges ofthe corner cover plates rest upon the upper flanges of the side coverplates l5, the major portion of the weight of the corner cover platesand the concrete placed thereon is supported by the base 2O through thecover plates l5. The various apertures through which the form centerhooks pass are of such size that lateral pressure upon the cover platesis taken up not by the hooks 29, but by the engagement of the formcenter edges with the cover plate flanges. The purpose of the hooks isto keep the form centers stationary when the base members are driven outfrom under the form centers, as will presently be explained. The hooksare not intended to withstand lateral pressure upon the side coverplates.

After the form has been positioned and assembled as just described, theconcrete which isto form the top and side walls of the culvert or otherconcrete structure under construction is poured over and around the formcenter in the usual manner.

The lateral pressure of the concreteis taken up by the form centers, andnot by the hooks 29, because of the heretofore mentioned loose fitbetween the hooks and the cover plate apertures. Attention is alsodirected to the fact that the base member angles 17 eifectually preventthe .lateral pressure of the concrete from forcing the lower flanges ofthe side cover plates under the base members.

After this concrete has been permitted to set a sufiicient length oftime, the base members 'l2 are struck with a. maul or ax to drive themin the direction indicated by the feathered arrow of Fig. 2. Duc to thefact that the form center hooks 29 engage in apertures in the coverplate flanges as has been ust described the form centers remainstationary when the base members are so moved. As soon as the notches ofthe base members are moved directly under the several form centers, theform centers drop out of engagement with the several cover plates andthe entire form collapses. The inclined surfaces 19 of the base membersl2 coperating with the inclined bottom surfaces of the various formcenters materially facilitate the collapsing of the form, because of thefact that when the base members are struclr, as just described, there isno tendency for the several parts to wedge. In fact, there is a decidedtendency for the parts to loosen,the direct opposite of a tendency towedge.

At this point I will state that the means carried by the form centersfor spacing the base members 12 need not be in the form of the rivets 27heretofore described. Any suitable and equivalent means may be providedfor this purpose. For instance, in Figs. 6 and 7 I have shown thelingers for engaging the upper edges of the base meinbers as short metalangles 27a, which are welded, riveted, or otherwise suitably secured tothe under sides of the form center flanges 22. The angles 27a. performprecisely the same function as do the rivets 27 hereinbefore described.

In Figs. 8 and 9 I have illustrated the adaptation of my invention to aform considerably higher and wider than the form shown in the precedingfigures. The form of F iOs. 8 and 9 differs essentially from that sliownin the preceding figures only in the fact that more cover plates arerequired, and in the fact that different form centers are employed. Eachof the form centers of Figs. 8 and 9 is provided with a plurality ofhooks 29, 29, at each of its lateral edges.

These hooks coperate with the apertures in the side cover plates, forthe purpose of steadying these plates prior to the pouring of theconcrete therearound, and to hold the form centers steady when the basemembers are driven independently of the form centers when the form is tobe collapsed. It will be noted that all of the several side cover platesl5 of Figs. 8 and 9 except the lowerinost side cover plates restdirectly upon the cover plate therebeneath, with the result that theweight of all of the side vcover plates is supported by the floor orbase l 26, none of the weightof these parts being' carried by the formcenters 13. It will be noted that since the form centers of Figs. 8 and9 are considerably wider than the form centers of Figs. l to 5inclusive, the horizontal sides of the corner cover plates 14 do notconstitute a complete top for the form. For this reason I employ avplurality of top channel members l5, which may be the same in allrespects as the side cover plates l5. need not necessarily be providedwith apertures if they are intended always to be used as top coverplates. However, by providing the flanges of the top cover plates l5awith suitable apertures, these plates may be used interchangeably withthe side cover plates.

Vhile I have shown but two sizes of form centers embodying my invention,it will be understood that my invention contemplates the provision ofform centers of a great number of different sizes. prefer to manufactureand sell an equipment which is intended to be used in the constructionof the form of my invention in a large number of sizes. Such anequipment comprises a pair of base members 12, which may be utilized inerecting a formof any The flanges of the top cover plates l5 I mightstate that I-` size, a pair of corner cover plates 14, Which are alsocapable olbeing used in building a form of any size, as many of thechannel members 15 and 15a as may be required in connection with theform of largest size, and a plurality of sets of form centers 13, oneset of these form centers being provided for every size 'form that theequipment is intended to provide.

In Fig. 11 I have illustrated a modified form center construction. Inthis construction the l'orm center hooks shown at 29a are formedseparately from the form 'center plates, and are Welded or rivetedthereto. The lateral edges of the form center and plates are notchedadjacent to the bars 29a, as indicated at 28, in order to accommodatethe rover plate flanges, the notches being so conformed that lateralpressure oli the concrete upon the side cover plates 15 may be taken upby the form centers and not by the hoolrs, as hereinbefore described.

While l have illustrated my invention in a number of characteristicembodiments,it will be understood that l do not limit myself to thesespeciiic constructions, but de-V sire to cover all similar andequivalent con# structions coming Within the terms and spirit of theappended claims.

What l claim as new and desire to secure by Letters Patent of the UnitedStates is:

1, A form of the class described compris-- ing a pairof base members,each provided With a plurality oi notches in its upper edge, a pluralityof form centers, said form centers adapted to rest upon said basemembers at points adjacent said notches, means carmembers for spacingthe lower edges or the side cover plates from the base members, saidhooks having loose iits in their respective cover plate apertures, sothat lateral pressure upon the side cover plates is trans- A' mitteddirectly to the form centers and not to said hooks, together With cornercover plates of substantially L-shaped cross section, the vertical sidesof said corner cover plates being provided With flanges aperturedtoreceive the form center hooks, said form centers adapted to drop so thatthe Yaforesaid hooks become disengaged from the cover plates When thebase members are driven to positions such that their notches liedirectly beneath the form centers.

2.' A form of the class described compris ing a pair of base memberseach provided With a plurality of notches in its upper edge, a pluralityof form centers adapted to rest upon said base members at pointsadjacent said notches, means carried by said form centers to space saidbase members Without preventing longitudinal movement of the basemembers independently of the form centers,ptogether with cover platesadapted to engage and space said form centers, said form centersarranged to drop out of engagement With said cover'plates when said basemembers are driven to positions such that the base member notches liebeneath the form centers.y

8. Aform of the class described compris-- ing a pair or base memberseach provided with a plurality oit notches in its upper edge, aplurality of form centers adapted to rest directly upon said basemembers atpoints adjacent said notches, means carried by said formcenters to space said base members Without preventing longitudinalmovement of the base members independently of the form centers, togetherwith cover plates adapted to-engageand space said form cen ters, saidform centers arranged to drop out o1 engagement With said cover platesWhen said base members are driven to positions such that the base membernotches lie beneath the form centers.

1. ln a form of the class described, the combination with a plurality ofform centers, base members Whereon said form centers rest, said basemembers when movedindependently of the form centers adapted to permitthe form centers to drop to positions lower than the positions normallyoccupied thereby, hooks at the lateral edges of the form centers, andVside cover plates provided with flanges aperturedto receive said hooks,said side cover plates arranged to hold the form centers-stationary Whenthe base members are moved as aforesaid, said hooks arranged todisengage the said cover plates when the form centers drop.

5.V lln a form of the class described, the combination with a pluralityof form centers, base members Whereon said form centers rest, saidV basemembers when moved independently of the i'orm centers adapted to permitthe term centers to drop to positions lower than the positions normallyoccupied thereby, means carried by the form centers to space the basemembers from each other Without preventing longitudinal movement of thebase members independently of the form centers, hooks the lateral edgesof the form centers, and side cover plates provided with liangesapertured'to receive said hooks, said side cover plates arranged toholdthe form centers stationary when the base members are'moved asaforesaid, said hooks arranged to disengage the said cover plates whenthe form centers drop.`

6. 1n a :form or the class described, the

combinationV with a plurality of form centers, base members whereon saidform centers rest, said base members when movedindependently of the formcenters adapted to permit the form centers to drop to positions lowerthan the positions normally occupied thereby, hooks at the lateral edgesof the form centers, and side cover plates provided with flangesapertured to receive said hooks, v

said side cover plates arranged to hold the form centers stationary whenthe base members are moved as aforesaid, said hooks arranged todisengage the said cover plates when the form centers drop, said hooksarranged loosely to lit in their respective cover plate apertures sothat lateral pressure upon the said cover plates is transmitted directlyto the form centers through said flanges and not to said hooks.

7. ln a form of the class described, the combination with a plurality ofform centers, base members whereon said form centers rest, said basemembers when moved longitudinally independently of the form centersadapted to permit the form centers to drop to positions lower than thepositions normally occupied thereby, cover plates disposed at the sidesof said form centers, hooks at the lateral'edges of said form centers,said cover plates provided with apertured means engaged by said hooks,said hoolrs adapted to drop out of the apertures and thus disengage thecover plates when the form centers drop, as aforesaid.

8. ln a form of the class described, the combination with` a pluralityof form centers, base members whereon said form centers rest, said basemembers whenmoved longitudinally independently of the form centersadapted to permit the form centers to drop to positions lower than thepositions nor nally occupied thereby, means carried by the form centersto space the base members without preventing longitudinal movement ofthe base members independently of the form centers, cover platesdisposed at the sides of said form centers, hooks at the lateral edgesof said form centers, said cover plates provided with means engaged bysaid hoolrs, said hooks adapted to risengage the cover plates when theform centers drop, as aforesaid.

9. ln a form of the class described, the

combination with a plurality of form cen ters, of base members whereonsaid form centers rest, said base members, when moved independently ofthe form centers, adapted to permit thefform centers to drop topositions lower than the positions normally occupied thereby, hooks atthe lateral edges of the form centers and side cover pla-tes providedwith flanges apertured to receive said hooks, said hooks having loosefits in their respective cover plate apertures so that lateral pressureupon the side cover plates is 1 normally occupied thereby, means carriedby the form centers for spacingv the 'base members fromV each otherwithout preventing longitudinal movement of the base membersindependently of the form centers, side cover plates, and means forattaching the side cover plates to the form centers whereby the formcenters'are-held stationary when the base members are movedlongitudinally as aforesaid, said attaching means adapted to permit theform centers to `drop independently of the side cover plates when thebase members are moved to positions such that the form centers arepermitted to drop, as aforesaid.

1l. A form of the class described comprising a plurality of formcenters, supporting means whereon the form centers are carried, saidmeans adapted to be moved to permit the form centers to drop topositions lower than the positions normally occupied thereby, side coverplates disposed at the sides of said form centers but having theirweight carried by the surface on which said supporting means rests,flanges carried by said cover plates extending toward said form centersand engaging the same, and hooks carried by the form centers engaging invapertures `in said flanges, said hooks adapted to disengage saidflanges when the 4form centers drop, as aforesaid.

l2. A form of the class described comprising a plurality of form centersprovided at their lateral edges with upwardly projecting hooks, aplurality of cover plates provided with in-turned flanges adapted tobear against the form center edges, apertures in said iianges engaged bysaid hooks, and means for supporting said form centers, said meansadapted to be operated to permit the form center hooks to drop out of'said apertures, substantially as and for the purposeset forth.

13. A form of the class described comprising a plurality of form centersprovided at their lateral edges with upwardly projecting hooks, aplurality of cover plates provided with in-turned flanges adapted tobear against the form center edges, apertures in said flanges engagedyby said hooks, said hooks fitting loosely in said apertures, and meansfor Vsupporting said form centers, said means adapted to be operated topermit the form center hooks to drop out of said apertures,substantially as and for the purpose set forth.

Y the Vlatter stationary When the base members aremoved relatively tothe form centers.

l5. A form of the class described, comprising aplurality of formcenters, parallel base members Whereon the form centers are carried,saidbase members adapted to be moved to permit the form centers to dropto positions lowerthan the positions normally occupied thereby, sidecover plates disposed at the sides of said form centers but having theirWeight carried by the surface on' which said base members rest, saidside cover plates and termv centers having interengaging members whichare adapted to disengage when the form centers drop as aforesaid andmeans carried by the base members and projecting laterally therefrom toengage the lovvermost side cover plates near the lower edges thereoi2 toprevent the lowermost side cover plates from being forced by lateralpressure out of alinement With the cover plates thereabove. l v

In Witness whereof, I hereunto subscribe my namethis 6th day of April,1920.

HARRY ErBILGER.

Witnesses: Y

E. LOUISE SNYDER, ANNA PAYNE. o

